An optical glucose biosensor based on derived glucose oxidase immobilised onto a sol-gel matrix

Glucose oxidase, firstly covalently bonded to a fluorescein derivative, is immobilised onto a sol-gel matrix. During the enzymatic reaction, glucose r eacts with the labelled enzyme and when the oxygen dissolved in the solutio n is consumed, an increase in the fluorescence intensity of the labelled en zyme is observed. The time at which the variation in the fluorescence inten sity is observed is directly related to the glucose concentration, and it w as therefore used as the analytical parameter for glucose quantification. T he protocol of sol-gel formation is also optimised. The sol-gel presents a dynamic response range from 100 to 1000 mg/l with a lifetime of 15 days. (C ) 1999 Elsevier Science S.A. All rights reserved.